Question

If the cost of 18 books is 672, then find the cost of 15 such books.​

Answer 1

Answer:

560

Step-by-step explanation:

Given,

Cost of 18 books : 672

We have to find the cost of 15 books.

So,

The cost of 3 books = 672/6        {Since, the cost of 18/6 books is 672/6}

                                ⇒ 112

Not that we have found the cost of 3 books, the cost of 15 would be:

112 × 5            {Since, the cost of 3 × 5 books is 112 ×5}

⇒ 560

∴ The cost of 15 books is 560.

Answer 2

Answer:

Hence cost of 15 such books will be Rs 560

Step-by-step explanation:

In context to questions asked

We have to determine the cost of 15 books

As per questions

Cost of 18 books is Rs 672

So for determining the cost of 15 books we will first determine the cost of 1 book

So for determining the cost of 1 book we will divide 672 by 18

Thus cost of 1 book will be

$\frac{672}{18} = 37.333 =37 \frac{1}{3} = 37. \bar 3 \: rs$

So cost of 15 such books will be,

$37 \frac{1}{3} \times 15 \\ = > \frac{112}{3} \times 15 \\ = > 112 \times 5 \\ = > 560 \: rs$